Dust classifier



April 23, 1929. I HARbING 1,709,848

DUST CLAS S IFIER Filed Aug. 28; 1925 4 Sheets-Sheet 1 INVEN TOR. BZMWL W C W/wv, /-V 401.

A TTORNEYS.

April 23, 1929. H. HARDINGE DUST CLASSIFIZER Filed Aug. 28. 1925 4 Sheets-Sheet INVENTOR.

W/d/m/v AT'IORNEYS,

April- 23, 1929; HAR'DINGE 'DHS'I .CLASSIFIER Filed Aug. .28. 1925 4 Sheets-Sheet 4 awpwboz 5 Patented Apr. 23,- 1929.

- 1,709,848 Price.

EARLOWE HARDING-E, OF YORK, PENNSYLVANIA, ASSIGNOR TO HARDINGE COMPANY, INCORPORATED, OF YORK, PENNSYLVANIA, A CORPORATION OF NEW YORK.

DUST CLASSIFIEB.

Application filed August 28, 1925. Serial No. 53,174.

This invention relates to classifiers such as are used in the classification and the extraction of coarse material and fine material from a body of material laden air or other buoyant or elastic fluid capable of carrying .particles ,in suspension.

Heretofore, classifiers of the air current and cone-shaped variety and other varieties of two compartment classifiers have been used, but these have been of such inflexible design that a very narrow range of adjustment was possible and the result was that the classifier designed for the classification of a particular material was at its best efficiency when a certain grade of powderof that material was being produced. It is among 'my purposes of invention to be able to use an apparatus of the cone-shaped variety or of any other variety having two compartments for classifying ditferentsubstances and different grades of the same substance efliciently, and to obtain this result by making the various parts relatively adjustable so as to create the best condition for the different classifications. 1

Another object resides in-providing a gen eral assembly comprising a dust classifier susceptible to being adjusted for the separation of dust of Various degrees of fineness, together with a disintegrating mill which serves the purpose of pulverizing coarse material, a cyclone or dust collector for the purpose of collecting the product/ of separation in the form of dust, and connections therebetween including a blower to maintain a dust carrying fluid in circulation throughout the entire assembly and dampers and valves to aid in the proper distribution and necessary regulation of the pressure of the moving mass of dust carrying fluid throughout the assembly. Another object of the invention resides in the provisionof a two-cone separator capabl of relative adjustment for varying the lifting capacity of theair passing between the cones.

Another object resides in the design of defleeting blades such as will cause various degrees of fineness of material to be'separated out from the current of material laden air ticular area of the surfaces of the blades that arerendered efi'ective. by being exposed to the passing current of materlal laden air.

. Another object is the provision of a valveless return passagei o. reconvey. oversize r nafrom the detailed description and drawings, in which, I

Fig. 1 is a general view showing the operainvention which :will be fully understood tive relation of the classifier with a rotating mill. T I

Fig. 2 is a sectional view of the classifier. Fig.3 is a perspective view of the top of the classifier looking from the inside and clearly showing a design of the deflector blades according to one modification. 1 Fig. 4 is a diagrammatic illustration of another modification of the arrangement of the deflector blades. Y Y r Fig. 5 is an elevation of a general assembly illustratinga third modification of a manner of exposing various amounts of surface of the deflector blades to passing currents of I have chosen to describe my invention according to a preferred, working combination, and this is illustrated in Fig. 1,'wherein the classifier is directly connected to the discharge endof a rotating mill 1 from which a stream of material laden air or other fluid is conmeans of hopper 2 and owing to its rotary motion and design the finely pulverized material seeks the surface and approaches the;-

dischargeend. Air is blown into the rotat-' ing mill from conduit 3, through a sectiomof pipe 4, and it leaves the mill by. following a path along the outside of pipe 'tand through a barrel 5 into a conduit leadin tothe classifier. In the mill, the pulverized material is continually being agitated b the/rotation of the mill and the moving air ecomes laden with material and is'then drawn through the barrel where the coarse particles drop out. Some, of. the pulverized material may overfiowat the discharge end of. the mill and fall.

into the barrel 5. The rotation of the barrel to be raised in a manner similar to the process recurring in the mill, and this material isv .1 causes the material that has dropped into it, v

1 its carrying capacity of fine material.

not necessary that my improved classifier be,

used with this type of mill, but. satisfactory result have been attained through use of the combination described.'

In order to control the flow of air "through the classifier a fan 6 is provided which-is 'flV-ltlllll the inner cone.

In the embodiment illustrated ,in Fig. 2 80 there is fastened to the inner side ofthe inner driven by amotor 7. This fan draws from the top of the classifier through pipe conn'ec-ii. tion 8 and discharges a steady stream of air, laden with an impalpable powder, into a collector 9 which may be of any desirable-de- 5 sign, such as that of the well known cyclone yr i Referring more particularly to the classi her, 10 is the exterior cone which forms the envelope summing the meansby the use and adjustment of which powdered products of varied fineness are obtainable; This-cone may be made rigid enough to support itself or be supported by any suitable structure, and it has near its apex a large opening through which a rapidly moving stream of n'laterial-laden air enters This opening is. connected to. the barrelof the mill by a con-.1 duit 11 andlall the material that enters the. classifier comes through this-conduit.

lower end of the cone forms a pocket 12 which opens into the airfeed duct 3 of the mill, and all of the over-sized material which is sep ,arated out from the air current passing I through [the classifier is exhausted through the pocket and into the duct. Just below the pocket exhaust opening there is an adjustable bafile 13 for constricting the area of the duct at this point which causes an increase in the velocity of flow of air in the duct and a com .'sequent increased exhausting effect froni the interior of the cone. U Centrally located within the .outer .conej; is suspended an inner cone 14; entirely open at its top and having aJarge opening at its apex. It is not of the same slope as the outer cone "and its upper end 15 is cylindrical.

L The opening in the bottom the inner.-

cone is-partially closed except for an annular openinglcreated by a" conically shaped member'flfiwhich is adjustable relatively to.

the inner cone 'for varying the size of the opening.

This member may be shaped substantially as shown in Fig. 2 and it is loosely mounted on a rod 17 passing through its axis. The upper end-of the rod is fastened to a bar 18 which extends to'the inner walls of the cone 14 and is fastened thereto by suitable means such as rivets. The lower end of rod 17 is maintainedsin a definite vertical posit'on by e brace 19. A satisfactory manner 0 posi- It is Y the upper edge of the inner cone.

able manner of fastening may be provided, 85

tioning the member 16 is by sliding it up or down on rod 17 and locking it in the desired position by means of a large cotter pin or the like passing through holes in the neck 20 and rod 17. A door 21 may be provided for ing than that in the area opposite the central ,girth of the conical member with the result that the tendency ofthe air is to follow along the areabetween the two cones and not enter cone andnear its top a tubular member 22 with its uppercdge on or about a level with Any suitas for example, straps 23, which I have chosen to show in this embodiment.

The top of the outer cone consists of a truncated cone 24 having a flange 25 at its base creating a detachable connection with the outer cone 10, and having a neck orpipe 26 connecting it with the exhaust pipe 8. \Vithinthisneck or pipe there is a sleeve 27 which extends into'the inner chamber and has supported therefrom a closure member 28 consisting of two cones arranged base to base and supported by the suspension rods 29 fastened to sleeve 27. The size of the exhaust.

3 opening is dependent upon-the position of the closure member and this position is adjustable by lock nuts 30 on each rod. The closure opening also eliminates eddy currents at this point and deflects the air in the proper directions.

Fastened to top 24; are a plurality of deflector blades 31 of twisted configuration and equidistant from one another (Fig. 3). Their lower endsare maintained inspaced relation by a ring 32. The lower part of each deflector 31 extends downwardly betweenthe concentric walls 15 and 22, and the annular areacovered by a horizontal crosssection of all of thedeflector blades at any place does not exceed the annular area between the vertical walls 15 and 22. This arrangement allowsfor an adjustment of the surface of the,=defleetor blades that is .tobe exposed for purposes that will. appear hereinafter.

. The lower edge of each blade is radially disposed and the top edges are preferably much longer, and, in this embodiment, make an angle of a little'less than 90 with the radial edge. The angularity and length of the top edges is dependent upon the maximum whirling motion desired and is subject to alteration depending upon the capacity ofthe apparatus used and the fineness of material to be produced. The surface between the upper and lower edges of each deflector is curved in such a manner as to give a whirling motion to the passing air, the intensity of which depends on the amount of vertical deflector surface which is exposed to the current of air. If the inner cone is in a low position, the passing air will be but slightly whirled, but if the top of the inner cone an member 22 are ina raised position the whirling motion will be greater, for all of the air must pass through the part of the deflectors which gives it the greatest change in direction. Hence, the effective surface of the .deflector is determined by thearea that is cov- -ered and comprises-the area exposed to the passing currents of air. 4

' The inner cone and its attached appurtenances is suspended byrods 33. Each is secured at its lower end to bar 18 and the upper end is threaded and passed through a boss j 34. A nut carrying a handwheel 35 forms a means by which the cone is raised or lowered.

The length of sleeve 27 has some effecton the selectivity of the classifier and the open end may be positioned in the approximate 'position'illustrated in Fig. 2 or in a raised or lowered positiondepending upon the material that is being produced.

In Fig. 4 I have illustrated a modified form of my invention, in which the deflector blades are contiguous with and preferably fastened directly to the outer cone along their outer edges and lJO lJlIG COIIG top along their upper edges. and the cylindrical wall 15 of the inner com is within the circle described by the inside edges of the blades. The deflector blades are of a twisted configuration similar to the construction described hereinbefore, except that the horizontal projection of the inner edges describes a circle of slightly greater diameter than the outer diameter of cylindrical wall 15. No member such as collar 22 is necessary in this construction, for the vertical ex posure of the blades is controlled entirely by the position of the inner cone which may be raised and lowered'for the purpose.

The material of which the cones and ducts are made comprises preferably sheet metal of suflicient weight to obtain rigidity and strength in construction, and is lapped, riveted, and preferably soldered or welded so as to be certain ofan air-tight condition. It.

is obvious thatmany. other ways of construction are adaptable without departing from thespirit of the invention.

- During the process of classification of various grades of material, a current of air,

. or of any other suitable fluidv medium that will carry by its motion pulverized material,- is drawn into the inletll of the outer cone directly from a mill where the raw material is pulverized. When-it enters from the inlet it. flows into a crosssectional' area larger than'the inlet duct and its velocity is correspondingly decreased. This allows the collect in the of separation of dusts accomplished by' varycoarser pieces to' drop and pocket near the apex of the outer cone from whence they are drawn into the air feed duct for the mill and returned for further crushing. The finer particles are carried along by the current of air between the two cone surfaces and through the deflectors. The curd rent of air will then be whirled by the deflec-v tors an amount depending on the distance of the top of the inner cone from the roof with a consequent drop in velocity, thereby creating a reduction in lifting capacity of the moving air. In the raised posit-ion the smaller of the coarser particles will of themselves dro back to be reconveyed to the pulverizer. n this position of the inner cone, the lower part of thedefiectors will be eliminated from functioning and the materialladen air must pass through the deflectors at their greatest pitch. This will create a greater centrifugal action so that only very fine particles will be carried along with the air and out to the collector.

It is obvious that when the inner cone is in its lowest position a coarser product will result, for the velocity of the air rising between the two cones is' greater, and larger particles will be carried to the top. Also the deflectors are not covered to any extent and the air will not be given as great'a whirling .motion as when the cone is in a raised position, withthe result that a coarser product will be retained in the air current.

In Fig. 5 I have illustrated a general assembly differing from that illustrated in Fig.

1 and including still another modification of adjustable structure for causing a whirling niotion of passing currents of air. In this modification, the deflector blades are of the same style and disposed similarly to those illustrated in Fig. 4'. However, a collar 36 is introduced between the inner edges of the 'deflector blades and the cylindrical wall-15 icone couldbe fixed in relation tothe outer cone and all adjustment for difl'erent degrees ingthe effective area of the deflector blades by manipulation of the collar.

The delivery conduit 40 of the classifier leads directly into the product collector 41 in which the product is removed from the current of air and the air Withdrawn'from the collector through conduit 42 by fan 43. The exhaust of the fan is connected to the mill by conduit 3, and a vertically disposed pipe 44 exhausts Whatever extra air that is drawn into the system as a result of'infiltration.

This pipe is open at its upper end, and a valve 45 may be used to control the amount of air exhausted. Under certain conditions it is preferable to drive air into the classifier directly instead of forcing all of the air through the mill, and this is accomplished by the interpositioning of a by-pass conduit 46 between conduit 3 and conduit 11. Valve 47 is adjustable to regulate the amount of air phat will be delivered directly to the classiier.

My invention is capable of a wide variation and relationship of parts without departure from the nature and principle thereof, and I do not restrict myself unessentially in the foregoing or other particulars, but

contemplate such alterations and modifications within the scope of the appended claims as may be found to be advisable,

What I claim is:

1. In an apparatus of the class described, the combination of an outer cone and an illner cone relatively movable and so related in respect to one another as to allow a current of material-laden fluid to flow between their respective surfaces, said inner cone being open at the top and having disposed thereat in definite relation with the outer cone a set of deflectors of twisted configuration for controlling thewhirling effect of the material-laden fluid passing therethrough, and said outer cone having an opening at the bottom for the entrance of material-laden fluid and an exit at the top for the expul sion of the fine product suspended in a current of fluid after the coarser material has been extracted therefrom by the whirling action of the material-laden fluid passing through the deflectors.

2. In an apparatus of the class described, the combination of an outer cone and an inner cone relatively movable and so related in respect to one another as to allow a current of material-laden fluid to flow between their respective surfaces said inner cone being open at the top for permitting the fluid to enter the inner space of said cone and being closed att-he bottom by a conical member except for an annular opening through which passes oversize material discarded by the fluid current which i's'directed towards an exhaust pipe having an entrance through said outercone.

3. In an apparatus of the class described, the combination of an outer casing and an inner casing relatively movable and so related in respect to one another as to allow a current of material-laden fluid to flow between their respective surfaces, said inner casing being open at the top for permitting the fluid to enter the inner space of said casing and open at the bottom for permitting the discharge of oversize material, and means for restricting the opening at the bottom so proportioned as to deflect a rising current of material-laden fluid away from said openin 4. In an apparatus of the class described,

the combination of an outer cone and an inner cone relatively movable and so related in respect to one another as to allow a current of material-laden fluid to flow between their respective surfaces, said inner cone being open at the top for permitting the fluid to enter the inner space of said cone and being closed at the bottom by a conical member except for an annular opening through which may pass oversize material discarded by the fluid current, said outer cone having an entrance near its lower end for admitting said current of material-laden fluid,v.an exhaust at its upper end for conducting away the tine product suspended in fluid, and an opening at its lower portion for excluding the extracted coarser materials.

5. In an apparatus of the class described, in combination, an outer casing and a relatively movable inner casing, deflectors secured at the top of said outer casing and arranged concentric to the rim of said inner casing and having their lower edges substantially radiallydisposed and their uppercasing in respect to said outer casing and de-' flectors in order to expose a variable amount' of surface of said deflectors to the passage of fluid. I

6. In an apparatus of the class described, in combination, an outer casing and a relatively movable inner casing, deflectors dis posed intermediate the upper extremities of the two casings so as to affect all fluid passing therebetween, and means forcutting out a portion of said deflectors from functional relation with the fluid'currents,

7 In an apparatus of the class described, in combination, an outer casing and an inner casing, deflectors disposed at the upper extermitics of the two casings so as to affect the fluid passing therebetween, and means for varying the exposure of said deflectors to said passing fluid.

8. In an apparatus of the class described, in combination, an outer casing and a relatively movable inner casing, deflectors having a twisted configuration varying in pitch from one edge to another, and means in-cooperati've relation with said inner casing for rendering ineffective variable amounts of surface of said deflectors.

9. In an apparatus for classifying materials, comprising in combination an outer casing and an inner casing describing two spaces, deflectors disposed therebetween to aflect the passage of fluid from one space to another, and means for varying the efleetive surface of said deflectors to change the course of the passing currents of fluid.

10. In an apparatus for classifying materials, comprising in combination an outer casing and an inner casing describing two spaces,'deflectors disposed therebetween to affect the passage of fluid from one space to another, means for covering a portion of said deflectors, and adjusting means for moving said inner casing and for varying the amount of covered surfaces of said deflectors.

11. In an apparatus for classifying materials, comprising in combinationan outer casing and an inner casing describing two spaces, deflectors disposed therebetween to affect the passage of fluid from one space to another, means for covering a portion of said deflectors, and means for independently moving saidinner casing.

12. In an apparatus for classifying materials, comprising in combination, an outer casing and an inner casing describing two spaces, the'outer space being adapted to be varied in cross sectional area throughout its length, deflectors interposed in communication between the two spaces, and means for simultaneously varying the amount of cross 4 sectional area and the eflective surface of the deflectors.

13. In an apparatus for. classifying material, an outer casing and an inner easing having an opening near its lower portion, a valve member normally extending within said opening and having a portion thereof of greater girth than the opening for preventing fluid currents from entering the inner casing throughsaid opening and permitting the discharge of solid material from the inner easing, and means for adjusting the relative position of the valve member.

14. In an apparatus of the class described, comprising, in combination, an outer casing having inlet and outlet openings, an inner casing having an open side for permitting material-laden fluid to enter from the outer side of said inner casing, deflectors disposed in the path of material-laden fluid flowing along the outer side of said inner easing, and means for varyingthe amount of area of said deflectors which is efi'ective to deflect the material-laden fluid flowing from between the inner and-outer casings and towards said open side of said inner casing.

15. In an apparatus of the class described, comprising in combination, a container for separating materials, said container having inlet and outlet openings, a casing'within said container, deflector blades intermediate said inlet and outlet openings,and means for varying the area of said deflector blades effcctive upon the fluid advancing toward said outlet opening.

16. In an apparatus of the class described, comprisingin combination, a container for separating materials, said container having inlet and outlet openings, a casing having 75 an opening therein, and a valve member for said opening, said valve member being conoidal and having two apices, one of which extends into said opening, and the other of which extends away from saidcasing whereby fluid currents are prevented from entering said inner casing through said opening.

In testimony whereof I hereto aflix my signature.

HARLOWE HARDINGE. 

